Caps and connectors with positioning cam and method of forming

ABSTRACT

The assembly of heavy duty caps and connectors is improved by incorporation of a wire clamp positioning ramp in the base of a clamp well in combination with a clamp restraining wall proximate the foot of the ramp. On gravity feed of a wire clamp into the well, the screw and clamp plate of the wire clamp are brought automatically into operation position. An electrode having a forked bottom end is then inserted into the well to straddle the shank of the screw of the wire clamp so that electric power is furnished to the electrode when a wire is gripped by the wire clamp.

United States Patent 11 1 1111 3,823,381 Maloof 1 1 July 9, 1974 [54] CAPS AND ONNE TORS T 3,335,395 8/1967 Smith 339/196 M x 3,461,417 8/1969 Schumacher et a1 339/14 P POSITIONING CAM AND METHOD OF 3,605,059 9/1971 Lipinski et a1. 339/263 R x FORMING Inventor: Robert E. Maloof, East Greenwich,

Assignee: General Electric Company, New

York, NY.

Filed: June 28, 1973 Appl. No.: 374,4l0

US. Cl. .."339/196 M, 29/629, 339/263 R, 339/278 R Int. Cl H011 3/00 Field of Search 29/629; 339/14, 65, 66, 339/154 R, 156 R, 196, 263, 278

References Cited UNITED STATES PATENTS 11/1941 Shenton 339/263 R X 5/1962 Howells 339/14 R Primary Examiner Bobby R. Gay

Assistant Examiner- Lawrence J. Staab Attorney, Agent, or FirmP. E. Rochford; P. L. Schlamp [5 7] ABSTRACT The assembly of heavy duty caps and connectors is improved by incorporation of a wire clamp positioning ramp in the base of a clamp well in combination with a clamp restraining wall proximate the foot of the ramp. On gravity feed of a wire clamp into the well, the screw and clamp plate of the wire clamp are brought automatically into operation position. An electrode having a forked bottom end is then inserted into the well to straddle the shank of the screw-of the wire clamp so that electric power is furnished to the electrode when a wire is gripped by the wire clamp.

4 Claims, 6 Drawing Figures FATENTED 91974 FIGURE 2 FIGURE 4 FIGURE 6 CAPS AND CONNECTORS WITH POSITIONING CAM AND METHOD OF FORMING ful in temporary supply of electricity from stationary wall receptacles to apparatus using relatively higher levels of electric power, as for example electric motors or portable machinery, heating apparatus, etc.' More particularly it relates to the cap and connector devices 'used in association with heavier duty wire or cable and to the assembly and manufacture of such caps and con nector devices.

It is known that substantially high levels of electric power must often be supplied on a temporary basis to portable electric equipment such as large fans, drilling equipment, refrigeration equipment and other devices having high power electric motors or other electric loads using a relatively high level of power.

The construction of one such cap and connector is disclosed in US. Pat. No. 3,461,417 issued in the name of Walter C. Schumacher et al. andassigned to the same assignee as this application.

Problems have been encountered in the manufacture of such caps and connectors and particularly in assembly of those forms of these devices in which wire clamps of the devices are restrained in their movement within the wells in the insulating housings thereof wherein the wire clamps are located. 1

There are numerousother devices of this general type and some of the patentsthereon teach features relating to the holding of screws in restrained positions. Such U.S. Pats. are typified by Nos. 3,189,896 and 3,605,059.0ther patents also teach means for restraining movement by screws in wiring devices, including US. Pat. Nos. 3,229,242 and 2,899,524.

In a device of the type taught in the US. Pat. No.

3,461,417, wire conductors of a heavier gauge are aligned generally axially with the axis of a cylindrical insulating housing. An exposed end of each of the conductors is clamped in a wire clamp made up of a screw and a wire clamp plate. ln doing so, the wire is brought into contact with one end of an electrode which has a formation which straddles the shank of the screw of the wire clamp.

While the reinforced product as described in US. Pat. No. 3,461,417'performs very well for its intended purpose once assembled, it has been found that for the forms of the devices which include means to restrain movement of the wire clamp screws out of their wells, there are certain problems and inconveniences in the manufacture of the devices and particularly in the initial assembly of the devices during their manufacture.

Thus it has been found that for devices as disclosed in US. Pat. No. 3,461,417, the screws of the wire clamps tend to protrude from tool access slots priorto insertion of the wire and that the closure of the clamp can occur. without capture of the conductor, and accordingly without a suitable conductive contact between the wire and electrode.

For devices which include wire clamp restraining means in the form of means limiting outward movement of the screws beyond the outer perimeter of the insulating means, it has been found that in the assembly of the sub-assemblies of the devices, the wire clamps tend to get out of alignment so that the electrodes can not be assembled into place conveniently, economically and reliably.

Further, it has been found that when the forked electrode is driven into place in the well when the wire clamp is not properly positioned, the parts are de formed or broken or the drive machine becomes jammed.

'A further problem associated with the assembly is that more than one of the wire clamps must be positioned at one time and before the electrode is driven into place. If only one is out of place, the driving of the electrodes could cause mangling of the metal parts or fracture of the housing or jamming of the machine.

If the casing is shuffled to move one wire clamp to its outer position, this same motion will move the diametrically opposite clamp to its inner position where jamming and other damage can result as all electrodes are driven into place at the same time.

OBJECTS OF THE INVENTION It is accordingly one object of the present invention to provide a wiring device the assembly of which is convenient, economical and reliable.

Another object of the invention is to provide a novel method for assembly of connectors having wire clamps cooperating with electrodes.

A further object is to provide components of a wiring device which are readily assemblable into a cap or connector. 7

Other objects will be in'part apparent from and 'in part pointed out in the description which follows.

SUMMARY OF THE lNVENTlON In one of its aspects, the objects of this invention are achieved by providing a cap or connector for temporary power supply including means for attachment of electric cable to the cap or connector. The wire attachment means includes electrodes having electric contacts at one end and forked wireconnecting means at the other. The electrodes are held within an insulat ing housing made up of an electrode holder and a wire terminal cover. The electrode holder has openings through which electrodes extend for contact with electrodes of other devices and the wire terminal cover has terminal wells in which wire clamps are retained to hold conductors of power supply cables. The wire clamps include screws threaded through clamp plates and the wells have too] access openings at the outer walls of the wire tenninal cover. The tool access openings are of narrower width than the heads of screws of the wire clamps. The wells are equipped with clamp positioning ramps toensure that each clamp disposed in a well during assembly is urged into the outermost position. In this way damage to the wire clamp, to the insulating housing, to theelectrode driven into the well, or to the electrode drive equipment is avoided.

BRIEF DESCRIPT ION OF THE DRAWING FIG. lis an exploded perspective view of a cap showing a cable clamp and outer cover separated from an electrode housing with protruding electrodes.

FIG. 2 is a top plan view of the inner cover of the electrode housing showing some wire clamps and electrodes in place.

FIG. 3 is an exploded detailed perspective view of one of the wire clamp and one of the electrode wells of the inner cover appearing in FIG. 2 showing the relation of various parts thereof.

FIG. 4 is a detailed exploded elevational view partly in section of a wire clamp poised above a well of the inner cover.

FIG. 5 is a detailed elevational view of a clamp and a base of the well as seen in FIG. 4 with the clamp contacting a clamp ramp thereof.

FIG. 6 is a detailed elevational view similar to that of FIG. 5 but showing the wire clamp fully in place.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing an electrical cap as shown includes an outer cover 10 and cable clamp 12, and an insulating housing 14 in which electrodes 16 are housed, and contact portions 18 of which extend from the face of the housing 14. Details of the construction and function of clamp 12 and cover IO-are disclosed in U.S. Pat. No. 3,461,417 referenced above and do not form a part of this invention.

The insulating housing 14 is made up, as also explained in the above-referenced patent, of an insulating electrode holder 20 and an insulating inner cover 22. An assembly screw 24 holds these two parts of the insulating housing 14 together in actual use of the device.

Prior to assembly of cover 10 to the insulating housing 14, a cable, not shown, is inserted through cable clamp 12 and cover 10, and individual bared conductors of the cable are inserted each through one of a plurality of wire entry port 26 in the cover 10. The electrical connection of these conductors to the held end of electrodes 18 is accomplished by means of wire clamps as explained below.

After connection of conductors to the electrodes the cover 10 is brought into place over and about insulating housing 14 and the cover 10 is secured in place by turning assembly screws 30 upwardly in FIG. 1 into conforming threaded openings 32 in a metal backing plate 35 provided atop the cover 10. Clamp 12 is then secured about the cable insulation of the cable passing through clamp 12.

The relationship of the electrodes and wire clamps to the inner cover 14 of the insulating housing is more clearly illustrated in FIG. 2 wherein the inner cover 14 is shown in an inverted position relative to its position as illustrated in FIG. 1. Thus a screw 28 which appears at the bottom or front in FIG. 1 appears at the top or back as illustrated in FIG. 2.

Screw 28 and an associated clamp plate 44 constitute a wire clamp. The wire clamp is located at and operates at the held end or base 46 of an electrode 34 and is used to clamp a wire, not shown, in electrical engagement with the held end 46 of electrode 34. The wire clamp, made up of screw 28 and a clamp plate 44, is held in a wire clamp well 36 in insulating inner cover 14. The clamp is held in place by the held end 46 of electrode 34, the electrode being driven into the conforming slot 38 in cover 14 during assembly of the electrode and wire clamp into well 36. The particular electrode shown in well 36 is a grounding electrode and the wire clamp with which it is'associated is mounted in a side notch, not shown, in the held end 46 of electrode 34. The electrode 34 is driven into place simultaneously with the driving in of the other electrodes but does not have the advantage of simplicity of assembly developed for the other electrodes as explained below.

Two other screw clamp wells 40 and 42 are formed in the inner cover as illustrated in FIG. 2 and electrodes and wire clamps assembled into these wells are assembled in accordance with the present invention. An electrode 48 having a held end 54 and a free end 18C as well as a wire clamp, made up of a screw 50 and clamp plate 52, are shown in place in well 40.

No electrode or wire clamp is present in well 42 but the wire entry port 26 and a clamp positioning ramp are readily evident at the bottom of well 42. A tool access port 58 at the outer section of the well 42 permits manipulation as necessary of the screw of a wire clamp positioned in the well.

The significance and operation of the clamp positioning ramp 56 is described with reference to FIGS. 3 through 6 which illustrate in perspective and sectional views a well such as well 42 and the positioning of the wire clamp and electrode therein.

The assembly ofa wire clamp such as 60 and an electrode such as 62 into a well such as 42 is carried out with the axis of inner housing 14 in the vertical position. The well 42 itself is seen in perspective in FIG. 3 and in vertical section in FIGS. 4, 5 and 6 with some structural details omitted in FIGS. 5 and 6 for clarity of illustration.

As is evident from FIG. 3, the wire clamp 66 is inserted in well 42 preparatory to introducing electrode 62 therein. The electrode 62 has a forked lower or held end 66 and a central notch 68 which fits above and around the shank 70 of the screw of wire clamp 60. The electrode 62 is driven into place in oppositely disposed slots 72 of well 42 to develop a forced fit in the slots. As the driving of electrode 62 takes place, the head 78 of the screw of wire clamp 60 must be out of the way when the electrode is driven home. However the screw head 78 is restrained from movement out from the bottom of well 64 through tool access port 58 by the stops 74 near the outer perimeter of outer wall 76 of inner cover 14. Because the screw head 78 must be precisely positioned in a well such as 40 or 42 to avoid damage to a screw, or to the electrode or to cover 14 or to the electrode driving machine, the assembly of the wire clamp and electrode in the respective wells was found to be time consuming and costly as well as resulting in damaged parts or equipment, as discussed above. This is partly because the wire clamp is located at the bottom of a well such as 40 or 42 during assembly and it was found to be cumbersome and awkward for those assembling the devices to bring the wire clamp into precisely the right position to avoid the damage and other problems as discussed above. However, it was discovered that by incorporation of a ramp 56 in the base of well 42 that a wire clamp could be simply dropped into the well 42 and, due to contact of a screwhead, such as 78, with the inclined surface of ramp 56, the clamp 60 was positioned in the desired forward position in well 42. This desired forward position is with the head 78 abutting stops 74 and accordingly essentially outward from a position where the head 78 would be struck by end 66 of electrode 62.

The manner in which the automatic positioning is achieved is evident from FIGS. 4, 5 and 6 wherein a wire clamp is seen progressively in a pre-insertion position in FIG. 4; in a post-insertion but unadjusted position in FIG. 5; and in a fully adjusted position in FIG. 6 with electrode end 66 driven into place.

It is evident from the figures that ramp 56 is effective in positioning not only screwhead 78 and shank 70 but also clampplate 80. Thus'wire clamp 60 is automatically set into position for assembly of electrode 62 but also in position for entry of a wire, not shown, through wire entry port 26 into the desired position between clamp plate 80 and the held end 66 of electrode 62.

What l claim as novel and desire to secure by letters Patent of the United States is: i

1. In a wiring device a. having a generally cylindrical insulating housing,

b. said housing being axially separable into an electrode mount sub-assembly and an outer cable clamp and cover sub-assembly,

c. and said electrode mount sub-assembly including an insulating electrode holder and an insulating wire terminal inner cover and electrodes mounted therein,

(1. said holder and inner cover being axially separable,

e. said electrodes having a wire terminal section and a power contact section,

f. openings through said electrode holder to provide passages for power contact portions of said elec-' trodes,

g. and wire entry and tool access openings through said insulating wire terminal inner cover to wire clamp wells in said cover for introducing the conductors of a cable and for clamping them to the wire terminal section of said electrodes,

h. said wells being adapted to receive and retain by gravity wire clamps comprising a screw and a wire plate clamp threadably engaged together,

i. and said wells being adapted to receive and retain by frictional engagement the wire terminal sections of said electrodes,

j. the improvement which comprises a wedge-shaped guide integral with the wall of said inner cover at the bottom of at least one of said wells of said inner cover,

k. the narrow end of said wedge pointing toward the screw access opening of said inner cover,

i. and the pitch of said wedge being sufficient to cause the screwhead falling into contact with the upper ramp surface of said wedge to ride down said ramp surface into its position to the tool access opening.

2. The wiring device of claim 1 in which the tool access opening is provided with a stop to limit outward movement of the screw head.

3. The wiring device of claim 2 in which the stop is in the form of a ridge along the walls defining the tool access opening.

4. A method of assembly of heavy duty caps and connectors which comprises a. locating a portion of an insulating housing to place electrode wells thereof in an upright position,

b. assembling wire clamps by threading a clamp screw into a clamp plate,

0. introducing the wire clamps into the electrode wells to face the screwhead toward an access opening at the outer perimeter of the housing,

d. inducing outward movement of the wire clamp by disposing the screwhead on a ramp having a downward inclination toward the access opening,

e. straddling said wire clamp with a forked electrode to hold said screw in place, and

f. assembling an insulating closure to said portion of said housing. 

1. In a wiring device a. having a generally cylindrical insulating housing, b. said housing being axially separable into an electrode mount sub-assembly and an outer cable clamp and cover sub-assembly, c. and said electrode mount sub-assembly including an insulating electrode holder and an insulating wire terminal inner cover and electrodes mounted therein, d. said holder and inner cover being axially separable, e. said electrodes having a wire terminal section and a power contact section, f. openings through said electrode holder to provide passages for power contact portions of said electrodes, g. and wire entry and tool access openings through said insulating wire terminal inner cover to wire clamp wells in said cover for introducing the conductors of a cable and for clamping them to the wire terminal section of said electrodes, h. said wells being adapted to rEceive and retain by gravity wire clamps comprising a screw and a wire plate clamp threadably engaged together, i. and said wells being adapted to receive and retain by frictional engagement the wire terminal sections of said electrodes, j. the improvement which comprises a wedge-shaped guide integral with the wall of said inner cover at the bottom of at least one of said wells of said inner cover, k. the narrow end of said wedge pointing toward the screw access opening of said inner cover, i. and the pitch of said wedge being sufficient to cause the screwhead falling into contact with the upper ramp surface of said wedge to ride down said ramp surface into it''s position to the tool access opening.
 2. The wiring device of claim 1 in which the tool access opening is provided with a stop to limit outward movement of the screw head.
 3. The wiring device of claim 2 in which the stop is in the form of a ridge along the walls defining the tool access opening.
 4. A method of assembly of heavy duty caps and connectors which comprises a. locating a portion of an insulating housing to place electrode wells thereof in an upright position, b. assembling wire clamps by threading a clamp screw into a clamp plate, c. introducing the wire clamps into the electrode wells to face the screwhead toward an access opening at the outer perimeter of the housing, d. inducing outward movement of the wire clamp by disposing the screwhead on a ramp having a downward inclination toward the access opening, e. straddling said wire clamp with a forked electrode to hold said screw in place, and f. assembling an insulating closure to said portion of said housing. 